Collector tube rapper system



June 3, 1969 E. H. R. PEGG COLLECTOR TUBE RAPPER SYSTEM Filed May 8,1967 Figure Figure 2 w in mm as R. mu ffi T m f IM A M United StatesPatent US. Cl. 55300 4 Claims ABSTRACT OF THE DISCLOSURE Freely swingingpendulum members are spaced along and suspended from spaced apartreciprocable rapp r bars in a parallel row arrangement with thecollector tubes of a multi-type centrifugal separator unit. Each looselyhung pendulum member is actually spaced between a group of fourcollector tubes so that it will be capable of striking each of the fourtubes in a substantially uniform manner, With two tubes receiving impactas its particular supporting bar is pulled in one direction and theother two tubes being hit as the bar is move in the opposing direction.A plurality of movable rapper bar means may all be reciprocated from acommon motor operated rotating shaft.

The present invention relates to a rapping system for the collectortubes of a multiple tube centrifugal separator unit. More specifically,the present improved system utilizes loosely hung pendulum members asthe rapper means in a manner such that each pendulum will strike itsparticular adjacent tubes in the unit with a quite uniform impactregardless of imperfect alignment or positioning of each collector tube.

It is known that in certain particle collection installations, there canbe a build-up of collected material on the inside of each of the outercollector tubes of a multitube dust collector type unit. For instance,in the collection of fly ash from the burning of lignite in a steamgenerator, there will be fouling and plugging of the outer collectortubes of the separator unit from a build-up of collected material on theinside surfaces of these tubes. This condition will in turn cause anincrease in pressure drop across the entire collector and a decrease incollection efficiency.

There have been various schemes and devices for periodically striking orrapping the tubes of a centrifugal separator unit so as to precludeexcessive build-up of material in the tubes of the unit. Generally, theknown prior designs have utilized rotating shafts down between the rowsof tubes to effect the movement of hammers 0r rapper means adjacent eachtube. Such shafts and hammer means have required numerous moving partsand bearings within a zone having a particle laden or dirty atmosphereso that as a result there has been much faulty operation and highmaintenance costs. It should also be pointed out that with fixed shaftlocations and fixed position rapper means there will be a tendency tohave hard rapping on some tubes and light rapping on others, unless bychance there are perfect mountings and alignments of all collector tubesin a given tube sheet, as well as perfect alignment of the rapper means.

Summary of the invention It may be considered one object of the presentinvention to provide a rapper system which is simple to construct andmount and will accommodate itself to slight misalignment of collectortube mountings in any separator unit. It may also be considered anobject of the invention to utilize loosely hung pendulums as rappermembers in a system which does not require any precision bearings, andminimizes rotating members and parts of a machined nature within thedirty atmosphere of the particle collector unit.

In a broad aspect, the present invention provides in combination with amultiple tube centrifugal separator unit for a particle laden gaseousstream, Where such unit has a plurality of particle collector tubes froma common tube sheet therein, the improved rapper system in combinationwith the collector tubes, which comprises arranging said tubes in aneven numbered plurality of rows and in a two-way manner, suspending asubstantially horizontal and laterally movable rapper bar in betweenalternate rows of the collection tubes wherby to provide a rapper barfor each pair of tube rows in one direction, additionally hanging aplurality of freely suspended pendulum members from each of said movablerapper bars, said pendulum members being at a level and spaced laterallyalong each of said bars such that there are pendulum members betweenalternate rows of tubes with respect to the direction transverse to saidbars whereby each pendulum member is available to strike the exteriorwall of each of four adjacent collection tubes, positioning power drivenmeans adjacent at least one side of said separator unit and connectingsuch means to each of said movable rapper bars whereby each bar isreciprocated or oscillated longitudinally and each pendulum member iscaused to swing back and forth to strike adjacent tube walls in a freemoving self adjusting manner.

Air cylinder units, or a motor driven shaft means, all outside of themain housing or chamber for the separator unit can well serve as thepower means for linking to the movable rapper bars and there is nointent to limit the invention to one type of power system.

It should be pointed out, however, that the present system not onlyminimizes the problems of having bearings, gearing or moving partswithin a particle laden atmosphere, but it provides for an inexpensivereadily installed system that minimizes maintenance and repair problems.For example, the suspension means for the moving or reciprocating rapperbar means may be eyebolt members or punched bar stock connecting betweensimple pins or bolts from clip angles at the tube sheet and at therapper bar itself. The pendulum members which in turn are supported fromthe reciprocating rapper bar members may be of a simple inexpensivedesign and need not be limited to any one particular configuration ormethod of fabrication. Again a simple pin or bolt member may be used toconnect an upper eye-bolt portion of the pendulum to the rapper barmeans. The lower portion of the pendulum may have a laterally extendingplate member or other enlarged section to serve as a means forcontacting and rapping the adjacent collector tubes of the plurality ofparticle separator tubes.

Reference to the accompanying drawing and the following descriptionthereof will serve to illustrate one embodiment of the improvedsimplified rapper system of the present invention as well as point outadditional advantageous features for the use of loosely hung pendulummembers in such system.

Description of the drawing FIGURE '1 of the drawing shows a partialelevational view of the present improved pendulum type rapper system incombination with a plurality of collector tubes in a separator unit.

FIGURE 2 of the drawing is a partial plan View of the improved rappersystem, as indicated by the line 2-2 shown in FIGURE 1.

Referring now to both FIGURES l and 2 of the drawing, there is indicateda portion of a particle collection housing 1 having a substantiallyhorizontal tube sheet 2 for accommodating a plurality of centrifugal 3separator devices that in turn have a plurality of outer collector tubes3 from such tube sheet means 2. For purposes of describing the presentinvention, it is not deemed necessary that the separator unit inletmeans, cleaned gas outlet tube means, particle collection hopper etc.,be illustrated and, as a result, such details are not shown in thepresent drawing.

Generally, the outer particle collection tubes 3 which tend to becomeinternally fouled or plugged with sticky materials will have lowertapered end portions 3 that in turn will feed the centrifugallyseparated particulate material downwardly into an enlarged collectionhopper. Thus, there is somewhat greater spacings or open area betweencollector tubes adjacent their tapered lower portions and the pendulummembers may be suspended within this zone and have greater freedom ofmovement in effecting the contacting of the lower portion of each tube.As best shown in FIGURE 2 of the drawing, the collector tubes 3 arearranged in a plurality of rows in a two directional manner such thathorizontal and laterally movable rapper bars 4 may be arranged in onedirection between alternate rows of tubes 3. Actually, in theillustrated embodiment, each raper bar unit 4 comprises two spaced apartbar members 4' which straddle their hanger bar means 6 and connectthereto by pin means 5. The bars 6 are in turn suspended from supportclips or lug members 7 attached to the lower face of tube sheet means 2.Suitable bolts or pins 8 through hanger bars 6 and support means 7 serveto provide a pin connection and a resulting desired reciprocating typeof movement for bar means 4.

As best shown in FIGURE 1 of the drawing, a plurality of spaced apartpendulum members 9 are attached to the reciprocating bar means 4 by baror eye-bolt means 10 and pin means 11. These pendulum members 9 arespaced laterally along bar means 4 so as to be between every other rowof tubes in the direction transverse to that of such bar means 4 and, asa result, each pendulum member 9 will serve to contact four differentcollector tubes 3 along their lower portions thereof 3'. The arrangementof pendulum members 9 with respect to a surrounding cluster of fourcollector tubes 3 is best shown in plan view by FIGURE 2 of the drawing.

It may also be noted that the positioning of the pendulum members 9 withrespect to collector tubes 3 in FIGURE 2 of the drawing is such that thependulums are in a neutral position with respect to the first two rowsof tubes. However, the rapper bar member 4 and the pendulum members 9are shown in a position such that the latter are contacting two of thefour collector tubes in each grouping with respect to the third andforth rows of the unit. This positioning is accomplished by virtue ofthe particular arrangement of the arm means 14 from the shaft means 13and the connection to the end of the rapper bar means 4.

As one method of operating the reciprocable rapper bar members 4, thereis indicated a motor operated gear box unit 12 which connects throughshaft means 13 to the crank arm means 14. The latter attaches throughpin means 15 with connector bar means 16 which in turn have a pinconnection 19 with the end of rapper bar means 4. The dual or spacedapart crank arm means 14 and the multiple section shaft means 13 whichis held in place by suitable hearings or pillow-block means 17 willserve to carry the power from gear box 12 through the successivesections of shaft 13 across the entire width of the separator unit.Where desired, the crank arm locations on shaft means 13 may be suchthat all of the reciprocating bar means 4 are in a similar position;however, generally, the crank arm means 14 may be spaced at '90 withrespect to successive pairs thereof such that adjacent rapper bar means4 will be in different locations and cause a resulting striking ofcollector tubes by pendulum members 9 at different periods (aspreviously noted in connection with the location of the pendulum members9 in FIGURE 2 of the drawing).

In the operation of the present improved unit, it will be found that theutilization of the loosely hung pendulum members 9 from the pinconnections at 11 on bar members 4 will permit the pendulum to oscillateback and forth along with the reciprocating motion of the horizontal barmembers 4 to which they are attached. Thus, that there is a striking ofcollector tubes at one side of the pendulum and then on the otherregardless of misalignment of tubes or slight misalignment andpositioning of bar members and their accompanying pendulums. Fro-mmaintenance aspects, it will be noted that the only bearings required inthe present rapper system are those which are utilized in connectionwith the shaft sections 13 on the housing of the separator unit and thatsuch bearings may be actually placed outside of the collection hopperand, optionally, enclosed by a suitable weather protecting section 18.The pins or bolt means, such as 5, 8 and 11, utilized in connectionbetween the hanger rods 6 and the rapper bars 4, as well as betweenpendulum rods 10 and bar means 4, may not be of any precision type ofhearing or closely sized pin. Generally, loosely fitted bolts or pinmembers capable of making a suitable suspended connection between theinter-related parts will suffice.

In the present drawing, the enlarged portions of pendulum members 9 areindicated as being formed of circular plate-like sections held toeye-bolts or rod means 10; however, the pendulums may be of cast metalwhere it is found that such construction is more economical than beingfabricated of separate parts. Also, in a modified design, thereciprocable horizontal rapper bar members 4 need not be of the dual barconstruction comprising spaced members 4 but may be of a single rigidbar pivotally or hingedly connected to suitable hanger bar means on theside of the latter. The pendulum members are then, in turn, bolted tothe side portions of such single horizontal bar means.

Although not shown, the power supply means to gear box means 12connecting to the shaft means 13 may incorporate a time cycle controllerso that there is an automatic operation causing the rapper bar system tobe in motion only a portion of the time. The frequency of operation willgenerally be determined by the stickiness of the particulate materialcarrying through the separator unit and the tendency to collect on theinside of the collector tubes. At the same time, further adjustmentmeans may be provided in the timing or cycling of the pendulum movementsthrough the control of the gear box means 12 such that there is anaccompanying variation in r.p.m. transferred to the shaft means 13. As aresult, it is possible to provide a wide range of settings in theoperation of the rapper system so as to suit all types of conditions fordifferent units or for varying conditions in a particular installation.

In another method of operation, as noted briefly hereinbefore, the barmeans 4 may be reciprocated by movable rods from air cylinders and therecan be modification or elimination of rotating shafts and motor operatedgear box means, such as 12. The design and use of air cylinders, and thelike, are well known and it is not deemed necessary to illustrate an aircylinder piston rod connective with the bar means 4 or with linkage thatin turn connects with an end of each bar means 4.

I claim as my invention:

1. In a multiple tube centrifugal separator unit for a particle ladengaseous stream in which a plurality of particle collector tubes dependfrom a common tube sheet therein, and said tubes discharge particlesdown into collection hopper means, said tubes being arranged in an evennumbered plurality of rows and in a two-way manner, the improved rappersystem in combination with said collector tubes, which comprises, asubstantially horizontal and longitudinally movable rapper bar suspendedin between alternate rows of the collection tubes whereby to provide arapper bar for each pair of tube rows in one direction, a plurality offreely suspended pendulum members hanging from each of said movablerapper bars along the lengths thereof, each of said pendulum memberscomprising a rod member pivotally connected to its associated rapper barand a transverse disk-like member connecting with the lower end portionof said rod member centrally located of four adjacent collector tubeswhereby each of said pendulum member swings freely about a horizontalaxis extending transversely with respect to its associated rapper barand said pendulum members being at a level and spaced longitudinallyalong each of said bars such that there are pendulum members betweenalternate rows of tubes with respect to the direction transverse to saidbars whereby each pendulum member is available to strike the exteriorwall of each of four adjacent collection tubes, power driven meanspositioned adjacent at least one side of said separator unit operativelyconnected to each of said movable rapper bars for reciprocating each barlongitudinally and whereby each pendulum member is caused to swing backand forth in a longitudinal direction to strike adjacent tube walls in afree moving self adjusting manner.

2. The improved rapper system of claim 1 further characterized in that apower driven rotating shaft means is positioned along at least one sideof said separator unit and at substantially right angles to said movablerapper bars, and arm and linkage means from said shaft means connects toeach of said rapper bars whereby to reciprocate the latter.

3. The improved rapper system of claim 2 still further characterized inthat adjacent rapper bars connect with said rotating shaft means throughsaid arm and linkage means with the latter at different positions withrespect to said shaft for each rapper bar whereby the pendulum membersconnecting to adjacent rapper bars will be in different strikingpositions with respect to adjacent collector tubes.

4. The rapper system of claim 2 further characterized in that adjustablepower supply means connects with said rotating shaft means wherebyvarying rates of rotation may be given to said shaft and provideadjustment in the rapping rate from said pendulum members.

References Cited UNITED STATES PATENTS 2,192,250 3/1940 White 551 122,575,876 11/1951 Kausch 55296 3,394,531 7/1968 Andersen 55346 2,198,6184/1940 Horne 55112 2,370,444 2/1945 Bowman 55348 2,438,827 3/1948Shofiner 55348 2,702,090 2/1955 Brown et a1. 55112 3,321,892 5/1967Saint-Jacques 55300 HARRY B. THORNTON, Primary Examiner.

BERNARD NOZICK, Assistant Examiner.

